USAP-DC

This award supports a project to create new, unprecedented high-resolution atmospheric carbon dioxide (CO2) records spanning intervals of abrupt climate changes during the last glacial period and the early Holocene. The proposed work will utilize high-precision methods on existing ice cores from high accumulation sites such as Siple Dome and Byrd Station, Antarctica and will improve our understanding of how fast CO2 can change naturally, how its variations are linked with climate, and, combined with a coupled climate-carbon cycle model, will clarify the role of terrestrial and oceanic processes during past abrupt changes of climate and CO2. The intellectual merit of this work is that CO2 is the most important anthropogenic greenhouse gas and understanding its past variations, its sources and sinks, and how they are linked to climate change is a major goal of the climate research community. This project will produce high quality data on centennial to multi-decadal time scales. Such high-resolution work has not been conducted before because of insufficient analytical precision, slow experimental procedures in previous studies, or lack of available samples. The proposed research will complement future high-resolution studies from WAIS Divide ice cores and will provide ice core CO2 records for the target age intervals, which are in the zone of clathrate formation in the WAIS ice cores. Clathrate hydrate is a phase composed of air and ice. CO2 analyses have historically been less precise in clathrate ice than in ?bubbly ice? such as the Siple Dome ice core that will be analyzed in the proposed project. High quality, high-resolution results from specific intervals in Siple Dome that we propose to analyze will provide important data for verifying the WAIS Divide record. The broader impacts of the work are that current models show a large uncertainty of future climate-carbon cycle interactions. The results of this proposed work will be used for testing coupled carbon cycle-climate models and may contribute to reducing this uncertainty. The project will contribute to the training of several undergraduate students and a full-time technician. Both will learn analytical techniques and the basic science involved. Minorities and female students will be highly encouraged to participate in this project. Outreach efforts will include participation in news media interviews, at a local festival celebrating art, science and technology, and giving seminar presentations in the US and foreign countries. The OSU ice core laboratory has begun a collaboration with a regional science museum and is developing ideas to build an exhibition booth to make public be aware of climate change and ice core research. All data will be archived at the National Snow and Ice Data Center and at other similar archives per the OPP data policy.

Person	Role
Ahn, Jinho	Investigator
Brook, Edward J.	Co-Investigator

Antarctic Glaciology

Award # 0944764

NSIDC-0539_1
NSIDC-0527_1

None in the Database

Repository	Title (link)	Format(s)	Status
USAP-DC	High-resolution Atmospheric CO2 during 7.4-9.0 ka	None	exist
USAP-DC	Abrupt Change in Atmospheric CO2 During the Last Ice Age	None	exist

1. Bauska, T. K., Marcott, S. A., & Brook, E. J. (2021). Abrupt changes in the global carbon cycle during the last glacial period. Nature Geoscience, 14(2), 91–96. (doi:10.1038/s41561-020-00680-2)
2. Shin, J., Ahn, J., Chowdhry Beeman, J., Lee, H.-G., & Brook, E. J. (2021). Millennial variations of atmospheric CO<sub>2</sub> during the early Holocene (11.7–7.4 ka). (doi:10.5194/cp-2021-113)